蛭石在低濃度鹽酸和硫酸中的溶出性比較研究

張玉 孫紅娟 彭同江 羅利明

蛭石作為三八面體層狀硅酸鹽礦物，由于其獨特的層狀結構被廣泛應用于各領域. 酸處理蛭石能提高蛭石的比表面積，改變層電荷數，達到增加表面活性官能團的目的. 以新疆尉犁蛭石為原料，在低濃度鹽酸和硫酸界面進行溶出性比較研究，對原料及酸浸后樣品的物相、結構、微觀形貌以及浸出液中各離子濃度進行表征分析. 結果表明：在酸濃度較低時鹽酸和硫酸對蛭石的酸蝕程度相當，在酸濃度稍微增加時硫酸對蛭石的酸蝕速度快于鹽酸. 兩種酸的蛭石結構中各金屬離子浸出的難易順序一致，均為：層間物>八面體片>四面體片.Ca2+作為層間陽離子在酸浸前4 h的溶出速率遠大于八面體陽離子Mg2+和四面體陽離子Al3+，且層間物中Ca2+相比于K+更容易浸出.適當的酸處理可以提高蛭石的陽離子交換容量. 本文對于蛭石的利用開發具有一定意義.

蛭石； 酸處理； 結構變化； 溶出效果

TQ170.1A2023.015001

收稿日期： 2022-04-19

基金項目： 國家自然科學基金（42072048， 42002039）

作者簡介： 張玉（1998-）， 女， 四川眉山人， 碩士研究生， 研究方向為環境科學與工程. E-mail： 1653651783@qq.com

通訊作者： 孫紅娟. E-mail： sunhongjuan@swust.edu.cn

Comparison of dissolution of vermiculite in low concentration hydrochloric acid and sulfuric acid

ZHANG Yu1，2， SUN Hong-Juan1，2， PENG Tong-Jiang1，2，3， LUO Li-Ming1，2

（1. Key Laboratory of Solid Waste Treatment and Resource Recycle， Ministry of Education， Southwest University of Science and Technology， Mianyang 621010， China;

2. Institute of Mineral Materials and Application， Southwest University of Science and Technology， Mianyang 621010， China;

3. Analytical and Testing Center， Southwest University of Science and Technology， Mianyang 621010， China）

As a trioctahedral layered silicate mineral， vermiculite is widely used in various fields due to its unique layered structure. Acid treatment of vermiculite can increase the specific surface area of vermiculite， change the number of layer charges and increase the surface active functional groups. Using Xinjiang Yuli vermiculite as raw material， the comparative study of dissolution of vermiculite at the interface of low concentration hydrochloric acid and sulfuric acid was carried out. The phase， structure， spectral characteristics， microstructure and concentration of ions in the leaching solution of the raw materials and the samples after acid leaching were characterized and analyzed. The results show that the degree of vermiculite corrosion by HCl and H2SO4 is similar at low acid concentration， and the rate of vermiculite corrosion by sulfuric acid is faster than that by HCl at slightly increased acid concentration. The order of leaching difficulty of each metal in vermiculite structure is the same as that of interlayer > octahedral sheet > tetrahedral sheet. The dissolution rate of Ca2+ as interlayer cation at 4 hours before acid leaching was much higher than that of octahedral cation Mg2+ and tetrahedral cation Al3+， and Ca2+ is easier to leach from interlayer than K+. Appropriate acid treatment can improve the cation exchange capacity of vermiculite. This paper has certain significance for the utilization and development of vermiculite.

Vermiculite; Acid treatment; Structural change; Dissolution effect

1 引 言

蛭石是指結構單元層為2∶1型，層間具有水分子及可交換性陽離子的三八面體和二面體鋁硅酸鹽礦物，具有較強的吸附能力和陽離子交換能力［1］. 工業上所指的“蛭石”通常是一組灼燒時能發生劇烈體積膨脹的類云母層狀硅酸鹽礦物. 工業蛭石包括礦物學意義的蛭石，以及由金云母、黑云母和綠泥石晶層與蛭石晶層形成的規則或不規則間層礦物，它們的共同特征是在結構中均含有蛭石晶（文中均稱蛭石）. 蛭石廣泛應用于諸多領域，在農業上主要用作土壤改良劑和農藥（殺蟲劑、除草劑等）載體；環境方面……